Monday, January 23, 2012

Guest Post: Surgeon Chris Cobourn Defends Lap-Bands

Readers of my blog might remember a post from just last week in which I detailed the results of a case-matched sample of folks who received gastric bypasses vs. those who received gastric banding where the results were exceedingly favorable to the bypass. One of my readers and colleagues, Dr. Chris Cobourn the medical director of Toronto's Surgical Weight Loss Centre (where both lap-bands and gastric balloons are inserted) read the post and responded with a thoughtful rebuttal.

As is my practice here, I asked if it'd be alright if I posted it on the blog, and I've done so without commentary:
Good Morning Yoni:
I read your blog this morning with a little more than the usual interest and would appreciate the opportunity to give you some feedback on the Gastric Band vs. Gastric Bypass article that you reference, and some of the more relevant literature on this subject.  As a surgeon with extensive experience in Lap-Band surgery (LAGB), I think it is important to ensure your readers that Lap-Band surgery is nowhere near being “destroyed”.
The decision to have bariatric surgery is a serious one, and it is important that individuals be presented with a balanced approach and current information.  The senior author is Dr. Michel Suter from Switzerland.  Dr. Suter has published previous  articles (1)  in this field and has a reputation as being very critical of the Lap-Band.   Due to his early experience with the gastric band, Dr. Suter is no longer performing the procedure, so the current study is another reiteration of his original and now outdated experience.  I debated Dr. Suter on a panel at the IFSO meeting in Capri a few years ago, when he presented his series of 300 Lap-Bands performed over a 10 year period.  It is unfortunate that the results of such a limited experience, a number of years ago are published as representative of today’s technique and experience in high volume centres.
My specific concerns about this paper are:
·         This study is described as a Case-Matched study.  Although better than a random comparison, it does not have the strength or validity of a prospective randomized trial.  There have been very few randomized controlled trials comparing RYGB and LAGB.  I have included two of them as attachments for you to review.  Although these studies show better weight loss with RYGB compared to the Lap-Band, the authors raise important questions as to whether the difference in weight loss is clinically relevant.  Both procedures induce weight loss substantial enough to resolve comorbidities and improve health which is the obvious goal. 
·         All of the patients in this report had Lap-Band prior to June 2005 and thus all had the procedure prior to the introduction of the latest model of Lap-Band.  As well, an undisclosed number had their Lap-Band procedure with a technique that is no longer used.  The peri-gastric technique that was used was shown to have a higher risk of complications and has not been used for at least 8 years.
·         Recent research into the mechanism of action of the Lap-Band has changed the way we manage post operative counseling and band adjustments for our patients.  Again this has been shown to have a significant effect on reducing post operative complications.  The patients in this paper did not have the opportunity to benefit from this new knowledge and this has likely contributed to some of the problems that were discussed.
·         The authors spend very little time discussing the short term complications of the either procedure.  This is a significant omission when comparing LAGB and RYGB.  The short term complications of RYGB have been consistently demonstrated to be more common, and more severe when compared to LAGB.  As well, there is a definite mortality risk associated with RYGB that is not discussed or identified in the study.  The failure to define and document “major morbidity” is a conspicuous deficiency in this study.  The relevance of this study is diminished without this discussion.
In regards to the discussion of long term LAGB complications, I have a number  of comments:
o   The authors report a 10% incidence of esophageal dilatation.  This is extremely high when compared to the current literature.  It likely relates to the principles used in band adjustment and the type of older model of band that was used in this series.
o   The authors report a 7.7% incidence of band erosion. This again is extremely high.  At the Surgical Weight Loss Centre (SWLC), in our first 3500 bands our erosion rate is 7/3500 = 0.2%
o   Port catheter leak rate of 6.8%.  Once again this is very high.  Our rate in 3500 bands is 1.5%
o   The authors report a 6.8% incidence of band removal for various reasons.  Band intolerance at SWLC leading to explantation is < 1%.  The authors have a high rate of conversion  from band to other procedures such as RYGB and BPD.   In our practice, where quick and easy access to RYGB is not available, we continue to work with patients to resolve their problems rather than remove the band or convert.  This is a major contributing factor as to why our band removal rate is so low.
o   No comment is made about long term nutritional issues after RYGB, which are well described.  Failure to acknowledge and discuss this potentially serious complication is a weakness of the study if their intent was to truly compare the procedures.
o   The methodology used to compare long term complications is not well described.  Some of the LAGB complications may be duplicated.  As well, the severity of the complications is not accounted for.  It is not appropriate to assume that all complications are “equal” when some can lead to major surgery and major morbidity and others require only minimal intervention.
One of the areas not discussed in the Suter paper is the well recognized rate of weight regain, starting at about 3 years after RYGB surgery.  You get a hint of it by looking at Figure 1 in the paper but it was not discussed by the authors.  This is an important issue for bypass patients that is unfortunately rarely mentioned.  There is a good paper by O’Brien and colleagues comparing both band and bypass in the long term (2) that shows no statistical difference in excess weight loss after the first few years.
Despite the attention that this paper will attract, it is not a definitive statement on the subject.    I am not sure that there will ever be such a paper.  RYGB and Lap-Band are different procedure both designed to produce sustained and significant weight loss.  Both have been shown to be effective at doing so in high volume centres of excellence that provide the operations using the latest techniques and that provide comprehensive follow up care.
We are in the process of publishing our results showing weight loss results comparable with other major centres, and with a very low rate of both long and short term complications.  We have already published our low rate of short term complications with Lap Band surgery (3).
Lap-Band surgery is a reversible procedure which is a significant benefit, the benefit of which is underestimated.  If research leads to an effective non-invasive or pharmaceutical treatment for obesity, patients could have their La-Bands removed with a simple procedure and then embrace the new treatment option.  This option is not available to any other bariatric surgical procedures.
The risks of bypass and band are very different and well understood.  Although the weight loss may be more rapid, and potentially a little better with bypass, I do not believe there is consensus that the difference is clinically relevant.  Although band patients may have a higher chance of revision surgery, the revision procedures are rarely performed for serious or life threatening complications.  Lap Band surgery is reversible which may be a benefit, but may also  lead to a higher rate of conversion to other procedures if the  results are less than anticipated.  Realistic expectations should be established, and a full and frank discussion of the short and long term risks are critical and mandatory for both procedures.
I appreciate your time and would be happy to discuss this paper and all the issues around it at your convenience.
Best Wishes
Dr. Chris Cobourn | Medical Director and Surgeon
Surgical Weight Loss Centre
1.      A 10-year experience with laparoscopic gastric banding for morbid obesity: high long-term complication and failure rates    Obes Surg. 2006 Jul;16(7):829-35.
2.     Systematic review of medium-term weight loss after bariatric operations.  O'Brien PE, McPhail T, Chaston TB, Dixon JB. Obes Surg. 2006 Aug;16(8):1032-40.
3.    Laparoscopic gastric banding is safe in outpatient surgical centers.  Cobourn C, Mumford D, Chapman MA, Wells L. Obes Surg. 2010 Apr;20(4):415-22.